﻿// Copyright (c) Matthias Koch
//
// See the NOTICE file distributed with this work for additional information
// regarding copyright ownership.  rubicon licenses this file to you under 
// the Apache License, Version 2.0 (the "License"); you may not use this 
// file except in compliance with the License.  You may obtain a copy of the 
// License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software 
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the 
// License for the specific language governing permissions and limitations
// under the License.
// 

using System;
using System.IO;

using XValidation.Exceptions;

namespace XValidation.Validations
{
  public class FileExtensionValidation : IValidation
  {
    private readonly string _extension;

    public FileExtensionValidation (string extension)
    {
      _extension = extension;
    }

    public void Validate (object value, string paramName, IValidationContext context)
    {
      if (value is string)
        Validate (new FileInfo ((string) value), paramName, context);
      else
        throw new IncompatibleTypeException (typeof (string), paramName);
    }

    private void Validate (FileInfo fileInfo, string paramName)
    {
      if (fileInfo.Extension != _extension)
        throw new FileExtensionValidationException (_extension, paramName);
    }
  }
}